81698807 has 2 divisors, whose sum is σ = 81698808. Its totient is φ = 81698806.

The previous prime is 81698791. The next prime is 81698863. The reversal of 81698807 is 70889618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81698807 - 2⁴ = 81698791 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81698867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40849403 + 40849404.

It is an arithmetic number, because the mean of its divisors is an integer number (40849404).

Almost surely, 2^81698807 is an apocalyptic number.

81698807 is a deficient number, since it is larger than the sum of its proper divisors (1).

81698807 is an equidigital number, since it uses as much as digits as its factorization.

81698807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 193536, while the sum is 47.

The square root of 81698807 is about 9038.7392373052. The cubic root of 81698807 is about 433.9155742678.

The spelling of 81698807 in words is "eighty-one million, six hundred ninety-eight thousand, eight hundred seven".